The present invention relates to a magnetic disk drive (or a hard disk drive).
Magnetic recording with applying a thermal assist method therein, wherein heat equal to or greater than 200° C. and magnetic field are applied within a recording bit area or region, having diameter of about several tens nm on a magnetic disk, is expected to be a high-density recording method for a next generation, and various kinds of developments are made thereon.
At present, studies are made, widely, upon using a near-field light, as a means for rising up the very small or minute recording bit region on the magnetic disk up to high temperature, simultaneously. For generating such near-field light, it is necessary to introduce or guide a light into a near-field light converter element, which is disposed in vicinity of recording magnetism of a magnetic head. As a light source of that, it is studied to apply a semiconductor diode.
However, the semiconductor diode is known as the light source for enabling to output a concentrated light of a single wavelength, but at the same time, holding a problem that, because of the heat generation of itself as a heat source, an oscillation output thereof is lowered down with an increase of temperature. For that reason, cooling of the semiconductor laser is an important problem to be dissolved, in the magnetic disk drive according to the thermal assist method.
On the other hand, as the structure for installing that of the thermal assist method is disclosed a technology, in the following Patent Document 1, wherein an optical path is connected by a wave guide, for the purpose of heating a disk surface, from a light emission portion in the vicinity of a slider up to the semiconductor laser, which is mounted on a base through a substrate or a circuit board.
Also, in the following Patent Document 2 is disclosed the structures for mounting the semiconductor diode in the vicinity of a recording coil of the slider.
And also, in the following Patent Document 3 is disclosed the structures for mounting the semiconductor laser on an arm for supporting the slider, which does rocking motion with respect to the disk and builds up a recoding coil therein.